1. Field of the Invention
The present invention relates generally to chlorine generators, and more particularly to a portable chlorine generator that can be used in the field to generate chlorine from common salt to sanitize water.
2. Description of the Related Art
The lack of clean, potable water is a significant concern in many undeveloped and/or devastated areas, and particularly in areas affected by war or natural disasters such as hurricanes, earthquakes, volcanic eruption, etc. Unfortunately though, these areas frequently have shortages of electric power as well as water, and the ability to transport large sanitation units into such areas may also be limited. Moreover, the people available to operate water sanitation equipment in remote or devastated areas may not be trained or equipped to handle the hazardous chemicals that are generally required.
The most commonly used chemicals for sanitizing water are halogen oxidizers, particularly chlorine-containing compounds. Halogen-containing compounds are generally strong oxidizing agents, and are therefore effective against bacteria, fungi, and algae. Unfortunately though, their strong oxidizing power makes them hazardous to handle and to store, making their use in areas affected by war or natural disaster problematic at best.
A method for providing chlorine gas from common salt has been known for many years. In that method, the salt is xe2x80x9ccrackedxe2x80x9d in an electrochemical cell to provide chloride ions and sodium ions. The ions are separated by an ion-selective membrane that allows either hydroxyl ions or chloride ions to pass through, thus isolating sodium hydroxide in the electrolyte on one side, and chlorine gas in the electrolyte on the other.
One device for practicing this xe2x80x9cchlor-alkali cellxe2x80x9d technology is the SAFE-T- chlor on-site chlorine gas generator marketed by Chemical Injection Technologies, Inc. (xe2x80x9cCITxe2x80x9d). That system uses large buckets or drums as the anode chamber and the cathode chamber, and connects them with a series of hoses. While the CIT system may be effective for the large-scale generation of chlorine, it is not practical for use in the field as described above.
A need therefore exists for a portable chlorine generator that converts common salt to chlorine gas that can be used to sanitize water. The present invention addresses that need.
Briefly describing one aspect of the present invention, there is provided a portable apparatus for generating chlorine from common salt. The apparatus uses DC current to crack the salt in an electrochemical cell having an anode separated from a cathode by an ion-selective membrane. Water serves as the electrolyte.
The apparatus preferably comprises a base with a passageway in it, with a first liquid-holder in fluid communication with one end of the passageway, and a second liquid-holder in fluid communication with the other end of the passageway. An anode and a cathode are both disposed in the passageway, with an ion-selective membrane positioned between them.
The electrodes are preferably made of expanded titanium, and have an electrolyte-contacting portion positioned in the passageway, and an electrical connection portion extending outward away from the passageway. An electrode holder effective to sealingly hold the electrode in the passageway, and thereby to define the electrolyte-contacting portion and the electrical connection portion, is also preferably included on each electrode.
The ion-selective membrane is effective for preventing the passage of chloride ions through said membrane, so chlorine gas will collect in the anode side of the cell. From there, it can be released via a gas outlet communicating with the first liquid holder. A venturi may be used to facilitate the removal of chlorine gas from the generator.
Sight tubes to facilitate observation of the liquid levels in the liquid-holders may also be included, as may be a handle to facilitate carrying and/or hanging the generator.
One object of the present invention is to provide an inexpensive, durable, and easily portable chlorine generator that can be used in the field to sanitize water.
Other objects and advantages will be apparent from the following description.